In preparation for corneal surgery such as is commonly used for vision correction, it is necessary for the surgeon to have highly accurate information concerning the shape and thickness of the cornea throughout its surface. It has been conventional in the past to measure the contour and thickness of the cornea by optically or ultrasonically examining the cornea at a number of distinct points on its surface. The problem with this approach is that since the cornea is often quite irregular in shape and thickness, unappreciated variations in the measured parameters may occur between the measuring locations, and it is consequently possible that damage to the cornea may occur in surgery due to cuts of excessive or insufficient depth. Another problem arises from the fact that the cornea can move during the examination, and it is therefore difficult to correlate the various locations at which measurements are being taken in sequence.
It is therefore desirable to provide a method by which the contour and thickness of the cornea can be measured on a substantially continuous basis and in a manner in which eye movement during the measuring process is of little or no consequence.